This invention relates in general to a hydraulic machine, and more particularly to a rotary hydraulic gear machine which may be utilized as a pump or motor and has two revolving gears provided with meshing teeth.
It is known to provide machines of this general type with bearings which journal the gears for rotation, and to provide sealing elements that are interposed between the axial ends of the gears and the associated bearings and are pressed against the axial ends of the gears by fluid pressure that develops in operation between the sealing elements and the bearings that are adjacent to them. However, in this type of machine the pressure fluid will flow in the space between the bearings and the housing wall of the machine and finally leads to the development of fluid pressure fields between the bearings and the housing end cover. These fields, however, have no useful purpose, and in particular do not contribute to balancing any of the forces within the gear machine; they merely exert stresses upon the housing, the housing end cover and the screws or other devices which connect the housing and the end cover so that these components must be manufactured more strongly than would inherently be dictated by their function if it were not for these pressure fields. This means that the machine is not only more expensive, since more material is required than would otherwise be necessary, but also will have a greater weight and larger dimensions.